Electromagnet for safety valves and the like



June 28, 1966 J. SCHMID ETAL 3,258,659

ELECTROMAGNET FOR SAFETY VALVES AND THE LIKE Filed Sept. 24, 1963 F/GJ mima f f/ww we/f Hrm/M] United States Patent O 6 claims. (ci. 311-165) The present invention relates to electromagnets in general, and more particularly to an improved electromagnet which is especially suited for use in thermoelectrically operated safety valves for gas burners and the like. For example, the armature of the improved electromagnet may be utilized as a means for permitting automatic sealing of the safety valve when the flame of a gas burner is extinguished. Electromagnets which are utilized in such safety valves normally receive current from a 'suitable thermoelectric current generator which is placed into or near the flame of a gas burner and which automatically deenergizes the electromagnet when the flame is extinguished. Since the currents produced by such thermoelectric generators are rather Weak, the electromagnet must be very sensitive and must be constructed in such a Way that it will take full advantage of the weak current.

Accordingly, it is an important object of the present invention to provide a very compact electromagnet which is constructed and assembled in such a Way that its component parts cannot exert adverse influence `on the magnetic lield which develops when the electromagnet is energized.

Another object of the invention is to construct the electromagnet in such a way that the interior of its housing is sealed from the atmosphere so that a gaseous fluid or another fluid medium is prevented from entering the spa-ce which accommodates the core, the winding and the armature of the electromagnet.

A further object of our invention is to provide an electromagnet of the above outlined characteristics which is constructed in such a way that the contact which connects the winding with a thermoelectric current generator need not be carried by or connected with the core.

An additional object of the invention is to provide a novel fluidtight connection between the core and the carrier of the electromagnet and also to provide an improved but very simple iluidtight connection between the carrier and the contact of the electromagnet.

Still another object of the invention is to provide a very simple iiuidtight connection between the carrier and the housing of the electromagnet.

A concomitant object of the invention is to provide an electromagnet wherein the connection between the contact and the carrier may be established in a very simple manner before the carrier is connected with the core.

Still another object of the invention is to provide a novel connection between the winding and the contact and to establish the novel connection in such a way that parts adjacent to the contact need not be heated to elevated temperature.

With the above objects in view, one feature of our invention resides in the provision of an electromagnet which is particularly suited for use in thermoelectrically operated safety valves for gas burners and the like and whose armature may serve to automatically prevent a gaseous fuel from flowing to the burner as soon as the flame is extinguished, either accidentally or on purpose. The electromagnet comprises an open-ended housing, a core received in the housing and having a first portion or base located nearer to and a second portion includice ing one or more legs more distant from the open end of the housing, an armature received in the housing and arranged to move toward and away from the second portion of the core so that it may move a valve member toward or away from its seat, a carrier comprising an inner portion which extends into the open end of the core and abuts against the end face of the first core portion, cooperating clamping means respectively provided on the core adjacent to the end face of its iirst por-tion and on the inner portion of the carrier and arranged to sealingly secure the core to the carrier so that the end face of the first core portion remains in abutment with the inner portion of the carrier, a winding having convolutions surrounding the second portion of the core and including a terminal portion which extends through a bore provided in the first portion of the core, and a contact carried by and insulated from the carrier. This contact comprises a head which is outwardly adjacent to the car- Iier and which is electrically connected with the terminal portion of the winding so that it may send a current to the Winding when the contact is connected to a suitable thermoelectric current generator which is placed into or near the dame of the gas burner in order to produce a comparatively weak current as long as the flame is burning and to permit automatic closing of the safety valve when the flame is extinguished.

The bore in the first portion of the core has a very small diameter so that the provision of such bore in the core cannot influence the magnetic eld when the electromagnet is energized.

The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The improved electromagnet itself, however, both as to its cons-truction and'its mode of operation, together with additional features and advantages thereof, will be best understood from the follow- Ving detailed description of a specific embodiment with reference to the accompanying drawings, in'which:

FIG. l is an axial section through a thermoelectrically operated safety valve embodying an electromagnet which is constructed in accordance with our invention; and

FIG. 2 is an enlarged axial section through the electromagnet. n

Referring to the drawings, and first to FIG. 1, there `is shown a thermoelectrically operatedv safety valve which includes a casing 10 definingv an internal seat 11 of annular shape provided between the discharge end 'of a fluid-admitting nipple 13 and the intake end of a fluid-evacuating nipple 14. The seat 11 may be engaged by a disk-shaped valve member 12 having a stem 15 and biased by a resilient element here shown as a helical return spring 16 which tends to maintain the Valve member 12 in the sealing position of FIG. ,1 so vthat a fluid flowing into the nipple 13 and lling the left-hand portion of the casing 10 cannot flow past the seat 11 and into the nipple 14. It is assumed that the fluid is a gaseous fuel which is being supplied to the burner or burners of a gas range or the like.

The left-hand end portion of the valve stem 15 extends through the end wall 27a of a housing 27 which constitutes a component part of a novel electromagnet 21, see FIG. 2. This electromagnet comprises a platelike armature 22 which is inwardly adjacent to the end wall 27a and which is connected to the end portion Yof the stern 15 by a screw 15a or by a similar fastener. The housing 27 further accommodates a U-shaped core 24 including a first portion consisting of two legs 24a, 24b which extend toward the end wall 27a and which carry the convolutions of a winding 23'. The second portion or base 24e of the core 24 is secured to a specially congurated carrier 25 having an outer portion here shown as a flange 25a which is outwardly adjacent to the open end of the housing 27 and whose outer side 25A is preferably at. This carrier 25 further supports a rivetshaped contact 26 whose outer end portion or head 26a extends beyond the outer side 25A and which is conductively connected with the winding 23 so that it may supply electric current necessary to attract the armature 22 toward the core 24 and to thus maintain the valve member 12 in open position in which the valve member is spaced from the seat 11 and permits the fluid to ow from the nipple 13, through the seat 11 and into the nipple 14. The ange 25a is clamped between the externally threaded left-hand end portion a of the casing 10 and an internally threaded cap 28 which latter is provided with a tapped bore to take a threaded plug 29 which causes the terminal 30 of a conductor 31 to abut against the head 26a. The conductor 31 leads to a thermoelectric current generator 32 which is placed into or near the flame of a gas burner so that it normally produces a current which is sufficient to cause the core 24 to attract the armature 22 as long as the llame is burning. When the flame is extinguished for any reason, the generator 32 ceases to deliver current to the winding 23 and the spring 16 returns the valve member 12 into sealing engagement with the seat 11 to shut off the flow of gas to the nipple 14. The construction of the generator 32 is well known in the art and by itself forms no part of this invention. By rotating the plug 29, the operator may press the terminal 30 against the contact 26 to make sure that the conductor 31 is in satisfactory contact with the winding 23. It will be noted that the plug 29 is formed with a central bore for the insulating sheath of the conductor 31.

The safety valve of FIG. 1 further comprises a manually operable actuating device which may move the valve member 12 against the bias of the return spring 16. This manually operable actuating device comprises a pushbutton 33 which is reciproca'ble in the right-hand end portion 10b of the housing 10 and which is biased by a helical spring 35 -so that its push rod 34 is normally spaced from the Valve member 12. The push rod 34 carries a stop washer 34a which counteracts the bias of the spring 35 when the pushbutton 33 is in the inoperative position of FIG. l. When the operator desires to ignite the gas, he merely depresses the pushbutton 33 so that the rod 34 moves the valve member 12 away from the seat 11 and that a stream of -gas begins to flow into the nipple 14 and to the non-illustrated burner of the gas range. Once the gas is ignited, the -tlame heats the thermoelectric current generator 32 so that the latter sends a current to the winding 23 whereby the core 24 attracts the armature 22 and the valve member 12 remains in open position even though the pushbutton 33 is released. The stroke of the push rod 34 is preferably selected in such a way that the armature 22 may be moved into actual contact with the legs 24a, 24h of the core 24.

Referring again to FIG. 2, the electromagnet 21 is constructed in such a way that the connection between the carrie'r 25 and the core 24 cannot influence or iniluences Very little the magnetic ield which develops when the generator 32 sends a current to the coil 23. The annular inner portion 25h of the carrier 25 extends into the open end of the housing 27 and is formed with a at annular face 40 which abuts against the adjacent end face of the base 24e. At its inner end which is distant from the flange 25a, the carrier 25 is provided with an inwardly extending clamping element in the form of a collar 41 which overlies a radially outwardly extending clamping element or projection 42 of the base 24C. The carrier is further provided with an external clamping element or collar 41a which is overlapped by the inwardly extending edge portion 27b at the open end of the housing 27. The material of the housing 27 is deformable so that its edge portion 27b may be bent radially inwardly and thereby retains the annular inner portion 2511 of the carrier in the housing, i.e., the carrier 25 is clamped to the housing 27 in that the edge portion 27b is located between the collar 41a and ange 25a. The connection between the core 24 and the carrier 25 is of similar nature because the inner collar 41 is bent inwardly to overlap the projection 42 so that the outer side of the base 24C remains in abutment with the end face 40.

The carrier 25 is formed with a central aperture 44 whose -diameter exceeds the diameter of a tubular stud 43, the latter constituting the central portion of the contact 26 and serving to connect the head 26a with a small inner end portion 49 which overlaps a washer 48 located in the interior of the annular inner portion 25h and abutting against an annular insulator 47 which is placed against a centrally located bottom face 46 at the inner side of the flange 25a. The bottom face 46 is surrounded by the annular inner portion 2511 and in turn surrounds the aperture 44. The head 26a is insulated from the carrier 25 by a second annular insulator 45 which abuts against the outer side 25A of the flange 25a. The peripheral surface 2-5U of the flange 25a is fitted snugly into a complementary recess provided in the end portion 10u of the casing 10, see FIG. 1.

lt will be noted that the cooperating clamping elements 41, 42 which secure the carrier 25 to the core 24 are provided at the periphery and close t-o the o-uter end face of the core 24 so that such clamping elements cannot exert undue influence on the magnetic held.

The washer 48 and the insulators 45, 47 provide a fluidtight seal between the carrier 25 and contact 26, and it is preferred to select the diameter of the washer 48 in such a way that it overlaps a portion yof the bottom face 46. The contact 26 is assembled with the carrier 25 before t-he latter is connected with the core 24 and before the annular portion 25b is clamped to the 'housing 27 so that the inner end portion 49 may be upset to such an extent that it presses the washer 48 against the insullator i417 and that Iit causes the head 26a to bear against the insulator 45. The head 26a overlaps the outer side 25A of the flange 25a, and it 'will 'be noted that the tubular stud 43 is centered in the aperture 44. T-he bottom lface 46 is coplanar 'with t-he inner side 251 of the ange 25a. Of course, the clamping elements 27b, 41a provide a uidtight seal so that a gas cannot enter the interior of the housing 27. If desired, the seal between the contact 26 and the carrier 25 may be impro-ved by an O- ring 44a which is inserted into the aperture 44 so as to surround the stud 43 and to be deformed in response to deformation lof the inner end portion #49. The ring 44a is normally of circular cross section and is located 'between the linsulators 45, 47 when the contact 26 assumes the position of PIG. 2. The iluidti'ght connection between the carrier 25 and the contact 26 is independent of the core 24.

It will be noted that the carrier 25 comprises two annular shoulders one of which is adjacent to the annular face 40 and abuts against the base 24C and the other of which is adjacent to the .bottom face 46 and serves as an abutment for the insulator 47. Thus, the internal compartment of the carrier 25 expands in stepwise fashion in a direction toward the core 24 and its central zone communicates with the aperture 4'4.

One terminal portion 51 of the winding '23 extends into and is secured to the tubular stud `43 of the contact 26.

This terminal portion 51 also extends through a centrally located small-diameter bore 52 provided in the base 24C of the core 24. The other terminal portion 54 of the winding 23 yis anchored in the carrier 125 by extending into an axially parallel groove provided in the project-ion 41a. The outer side of the head 26a yis formed with a recess 53 which diverges conically outwardly in a direct-ion away from the central bore of the stud 43 and which accommodates a mass 55 of soft solder, this mass serving to provide a current-conducting connection between the terminal portion 51 and the head 26a. The use of soft solder is `of considerable advantage because the insulators 45, 47 need not be yheated to elevated temperature at the time the terminal portion 51 is secured to the head 26a so that the seal lbetween rthe pants 24, 25, 27 -is not effected at the time the mass 55 is introduced into the recess 53.

When the electromagnet 21 is properly inserted in the end portion -a of the housing 10 and when the plug 29 is tight, the terminal 30 of the conductor 31 is forced into the recess 53 and abuts against the mass 55 of soft solder to establish a satisfactory connection between the generator 32 and the Winding 23.

It goes w-ithout saying that the novel electromagnet may be manufactured in many sizes and shapes so that it may be used in different types of safety valves.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, Iby apply-ing current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic and specic aspects of this invention and, therefore, such adaptations should and are intended to ibe comprehended within the mean-ing and range of equivalence of the following claims.

What is claimed as new and Idesired to be secured by Letters Patent is:

1. An electromagnet, particularly for use in thermoelectrically operated safety valves for gas |burners and the like, comprising a housing having an open end; a core received in said housing and including a iirst portion nearer to and a second portion more distant from said open end, said tirst portion having one side facing said open end and further having a bore; an armature received in said housing and arranged to move toward and away from the second portion of said core; a valve member having a lstem extending through said housing and secured to said armature; a carrier comprising an outer portion having an router side and an inner portion extending into the open end of and secured to said housing, said inner portion having a face abutting against the tirst portion of said core; cooperating clamping means provided on said core and on said carrier and arranged to |maintain the inner portion of said carrier in abutment with the first portion of said core, said clamping means comprising a projection provided on the iirst portion of said core and adjacent to said face, and a Icollar provided on the inner portion lof said carrier and overlapping said projection; a winding having convolutions surrounding the second portion of said core and comprising a terminal portion extending through said bore; and a contact carried by said carrier and located entirely adjacent said one side of said first portion of said core, said contact having a portion `which is electrically connected with said terminal portion and a head adjacent to the Iouter s-ide of the outer portion of said carrier.

2. An electromagnet, particularly for use in thermoelectrically operated safety valves for gas burners and the like, comprising a housing having an open end; a core received in said housing and including a first portion nearer to and a second portion more distant from said open end, said rst portion having one side facing said open end and further having a bore; an armature received in said housing and arranged to move toward and away from the second portion of said core; a carrier comprising an inner portion extending into the open end of and secured to said housing, said inner por-tion abutting against said one side of the first portion of said core and said carrier further comprising an outer portion outwardly adjacent to the open end of said housing and having an aperture; cooperating clamping means provided on said core and on said carrier and arranged to maintain the inner portion of said carrier in abutment with said one side of the tirst portion of said core; a winding having convolutions surrounding the second portion of said core and comprising a terminal portion extending through said bore; a contact located in its entirety adjacent to said one side of said first portion and supported by said carrier, said contact comprising a tubular portion received in said aperture and receiving the terminal portion of said winding, an inner end portion rigid with said tubular portion and overlapping the inner side of said outer carrier portion, and a head outwardly adjacent to the outer portion of said carrier; and insulator means provided between said carrier and said contact.

3. An electromagnet, particularly for use in thermoelectrically operated safety valves for gas burners and the like, comprising a housing having an open end; a core received in said housing and including a first portion nearer to and a second portion more distant from said open end, said first portion having one side facing said open end and further having a bore; an armature received in said housing and arranged to move toward and away from the second portion of said core; a carrier comprising an annular inner portion extending into the open end of and secured to said housing, said inner portion abutting against said one side of the rst portion of said core and said carrier further comprising an outer portion outwardly adjacent to the open end of said housing, said outer portion having an inner side, an outer side, and an aperture extending between said inner side and said outer side; cooperating clamping means provided on said core and said carrier and arranged to maintain the inner portion of said carrier in abutment with the iirst portion of said core; a Winding having convolutions surrounding the second portion of said core and comprising a terminal portion extending through said bore; a tirst and a second annular insulator, said insulators surrounding said aperture and being respectively adjacent to the inner and outer sides of said outer carrier portion; and a contact located in its entirety adjacent to said one side of said iirst portion and comprising a first end portion overlapping said first insulator at the inner side of said outer carrier portion, a tubular central portion extending with play through said aperture and receiving the terminal portion of said winding, and a second end portion overlapping said second insulator at the outer side of said outer carrier portion.

4. An electromagnet, particularly for use in thermoelectrically operated safety valves for gas burners and the like, comprising a housing having an open end; a core received in said housing and including a first portion nearer to and a second portion more distant from said open end, said rst portion `having one side facing said open end and further having a bore; an armature received in said housing and arranged to move toward and away from the second portion of said core; a carrier comprising an annular inner por-tion extending into the open end of and secured to said housing, said inner portion abutting against said one side of the first portion of said core and said carrier further comprising an outer portion outwardly adjacent to the open end of said housing, said outer portion having an inner side, an outer side, and an aperture extending between said inner side and said outer side; cooperating clamping means provided on said core and said carrier and arranged to maintain the inner portion of said carrier in abutment with the rst portion of said core; a Winding having convolutions surrounding the second portion of said core and comprising a termi-nal portion extending through said bore; a first and a second annular insulator, said insulators surrounding said aperture and being respectively adjacent to the inner and outer sides of said outer carrier portion; a contact located in its entirety adjacent to said one side of said rst portion and comprising a rst end portion overlapping said irst insulator at the inner side of said outer carrier portion, a tubular central portion extending with play through said aperture and receiving the terminal portion of said winding, and a second end portion overlapping said second insulator at the outer side of said outer carrier portion; and a washer disposed between said rst insulator and said first end portion of said contact.

5. An electromagnet, particularly for use in thermoelectrically operated safety valves for gas yburners and the like, comprising a housing having an open end; a core received in said housing and including a irst portion nearer to and a second portion more distant from said open end, said first portion having one side facing said open end and further having a bore; an armature received in said housing and arranged to move toward and away from the second portion of said core; a carrier comprising an inner portion extending into the open end of and secured to said housing, said inner portion having an annular face abutting against said one side of the first portion of said core and said carrier further comprising an outer portion rigid with said inner portion and having a bottom face outwardly spaced from and surrounded by said annular face, said outer portion further having an outer side and an aperture extending between said outer side and said bottom face; cooperating clamping means provided on said core and on said carrier and arranged to maintain the inner portion of said carrier in abutment with the first portion of said core; a winding having convolutions surrounding the second portion of said core and comprising a terminal portion extending through said bore; and a contact located in its entirety adjacent to said one side of said first portion and carried by said carrier, said contact having a portion received in said aperture and electrically connected with said terminal portion and a head adjacent to the outer side of said outer carrier portion.

6. In an electromagnet, particularly of the type which may be utilized in thermoelectrically operated safety Valves for gas burners and the like, in combination, a housing having an open end and an inwardly extending circumferential marginal portion at said open end; a core received in said housing and having a portion adjacent to said open end, said portion being provided with a radially outwardly extending shoulder; a carrier comprising a iirst portion having a first side and a second side and an aperture extending from said first side to said second side, an annular portion rigid with and extending from the first side of said first portion so as to surround said aperture, said annular portion being received in said open end of said housing and having a iirst portion projecting radially outwardly and engaging said inwardly extending marginal portion of said housing to prevent withdrawal of said carrier from said housing, and further having a second portion projecting radially inwardly and overlapping said shoulder of said core to secure the latter to said carrier; a contact having a first end portion overlapping said first side, a second end portion overlapping said second side, and a tubular central portion received in said aperture; and insulator means for preventing the fiow of electric current between said first and `second sides and the respective end portions of said contact.

References Cited by the Examiner UNITED STATES PATENTS 2,756,371 7/1956 Holmes 317-165 2,840,095 6/ 1958 Thornbery 137-66 2,932,307 4/1960 Bydalek 137-66 FOREIGN PATENTS 834,837 5/ 1960 Great Britain.

BERNARD A. GILHEANY, Primary Examiner.

LARAMIE E. ASKIN, JOHN F. BURNS, Examiners. G. HARRIS, IR., Assistant Examiner. 

1. AN ELECTROMAGNET, PARTICULARLY FOR USE IN THERMOELECTRICALLY OPERATED SAFETY VALVES FOR GAS BURNERS AND THE LIKE, COMPRISING A HOUSING HAVING AN OPEN END; A CORE RECEIVED IN SAID HOUSING AND INCLUDING A FIRST PORTION NEARER TO AND A SECOND PORTION MORE DISTANT FROM SAID OPEN END, SAID FIRST PORTION HAVING ONE SIDE FACING SAID OPEN END AND FURTHER HAVING A BORE; AN ARMATURE RECEIVED IN SAID HOUSING AND ARRANGED TO MOVE TOWARD AND AWAY FROM THE SECOND PORTION OF SAID CORE; A VALVE MEMBER HAVING A STEM EXTENDING THROUGH SAID HOUSING AND SECURED TO SAID ARMATURE; A CARRIER COMPRISING AN OUTER PORTION HAVING AN OUTER SIDE AND AN INNER PORTION EXTENDING INTO THE OPEN END OF AND SECURED TO SAID HOUSING, SAID INNER PORTION HAVING A FACE ABUTTING AGAINST THE FIRST PORTION OF SAID CORE; COOPERATING CLAMPING MEANS PROVIDED ON SAID CORE AND ON SAID CARRIER AND ARRANGED TO MAINTAIN THE INNER PORTION OF SAID CARRIER IN ABUTMENT WITH THE FIRST PORTION OF SAID CORE, SAID CLAMPING MEANS COMPRISING A PROJECTION PROVIDED ON THE FIRST PORTION OF SAID CORE AND ADJACENT TO SAID FACE, AND A COLLAR PROVIDED ON THE INNER PORTION OF SAID CARRIER AND OVERLAPPING SAID PROJECTION; A WINDING HAVING CONVOLUTIONS SURROUNDING THE SECOND PORTION OF SAID CORE AND COMPRISING A TERMINAL PORTION EXTENDING THROUGH SAID BORE; AND A CONTACT CARRIED BY SAID CARRIER AND LOCATED ENTIRELY ADJACENT SAID ONE SIDE OF SAID FIRST PORTION OF SAID CORE, SAID CONTACT HAVING A PORTION WHICH IS ELECTRICALLY CONNECTED WITH SAID TERMINAL PORTION AND A HEAD ADJACENT TO THE OTHER SIDE OF THE OUTER PORTION OF SAID CARRIER. 